System and method for producing on demand high temperature water

ABSTRACT

A system and method for efficiently producing high flow rate on-demand hot water. The system utilizes on-demand hot water heaters, super heated water expansion tanks, and a high flow mixing valve.

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 60/757,713, entitled “SYSTEM AND METHOD FOR PRODUCING ON DEMANDHIGH TEMPERATURE WATER” filed on Jan. 10, 2006, having Jim McIllwain andHelen McIllwain, listed as the inventors, the entire content of which ishereby incorporated by reference.

BACKGROUND

The invention is generally related to a water heater system and methodof operating the water heater system. More specifically, the inventionrelates to an energy efficient water heater system for commercial ordomestic use that can produce a large scale amount of high temperaturewater on demand. The water heater system of this invention has a moreenergy efficient recovery rate than conventional large scale hot waterheaters.

Hotels, apartment complexes, restaurants, laundromats, and othercommercial business typically utilize large quantities of hot waterthroughout the business day. However, the demand for hot water variesgreatly with different times of the day and with different seasons ofthe year. The availability of hot water can have direct consequences tothe business owners. For example, hotels and apartment buildings mayexperience a large demand for hot water in the morning when most patronsare taking showers simultaneously, however, the same hotel or apartmentmay not experience a great demand for hot water the rest of the day.Restaurants may have a high demand for hot water to wash dishes duringthe breakfast, lunch, or dinner rush, but not during the rest of theday. Laundromats may have a higher demand for hot water on the weekendscompared to the weekdays.

The amount of energy that it takes to heat and maintain the temperatureof enough hot water to meet the demand during peak hours can beconsiderable. However, the cost of customers not returning to a businessbecause they were inconvenienced by the lack of hot water isconsiderably higher. Many businesses choose to purchase large scalewater heaters to maintain a sufficient hot water supply for the time ofday when the demand for hot water is high.

The Conventional Water Heaters. Generally, conventional water heatersand boilers include a steel tank, insulated by foam encased in a metaljacket. Cold water runs into the steel tank. The cold water can beheated by electrical heating elements or gas with heat exchangers to apredetermined temperature (i.e. 120° F.), which is maintained until thehot water is used. Maintaining the temperature of hot water in the tankcan be energy inefficient during non-peak times. To utilize the hotwater, a user can open a faucet and hot water exits the steel tankthrough a pipe connected to the faucet. While hot water is drained fromthe pipe, cold water mixes with the remaining hot water, which reducesthe temperature of the remaining water. Reducing the temperature of thewater in the tank is especially inefficient during times of peak demandfor hot water. During hot water usage, the temperature of the remainingwater is lower than the predetermined temperature, which activates theheating device to maintain the water at the pre-determined temperature.The amount of time it takes to reheat a specified number of gallons ofwater to the predetermined temperature is considered the recovery rate,and is generally measured in gallons/hour. Thus, in order to maintainenough hot water to meet any demand, the tank size can be increased orthe predetermined temperature can be increased. Both options areinefficient during non-peak hours. Thus, conventional water heaters havemany drawbacks including inefficient heating, easy loss of heat energy,low recovery rates, and high installation space requirements.

The average temperature of tap water varies throughout any given state,depending upon the location, elevation, and time of year. For thepurposes of these examples, a tap water temperature of 70° Fahrenheitwill be used. Therefore, to achieve a temperature of about 160°Fahrenheit at the faucet, the required rise would be about 90°.

For example, one commercially available water heater from Kenmore(Dallas, Tex.) is called the “Kenmore 98 Gallon Natural Gas CommercialWater Heater.” The Kenmore water heater offers a 98 gallon tank capacityhas an hourly input of about 75,000 BTU, and a recovery rate, at about a90° F. degree rise, of 78.8 gallons per hour (GPH). Thus, in order toinsure a recovery rate of about 800 gallons per hour, one would needabout 10 of similar water heaters, using about 800,000 BTU/hour, whichdoes not include the amount of energy required to keep the water at thepredetermined temperature for non-peak hours.

On Demand Heaters. In order to decrease the amount of energy that isrequired to heat and maintain the temperature of hot water during highdemand times, high efficiency on demand commercial water heaters havebeen introduced. These heaters produce hot water only when needed, soenergy to maintain the hot water at a predetermined temperature duringnon-peak hours is eliminated. For example, one commercially availablehigh efficiency water heater from Rinnai Inc. (Nagoya, Japan) is calledthe “Continuum” model 2532FFU. The Continuum is a temperature controlledcontinuous flow gas hot water heating system that offers a supply of hotwater through multiple outlets simultaneously. One Continuum unit has atypical hot water capacity of about 8.5 gallons per minute (“GPM”),which is enough to run about two showers and a third point of use at thesame time without any loss of temperature consistency. The Continuum hasa gas input of about 15,000 to about 180,000 BTU/hour with efficiency upto about 87%.

It is also possible to increase the hot water capacity by using multipleContinuum units. When multiple water heaters are connected, they must beinstalled in parallel, not in series. The capacity of single andmultiple water heaters is shown in the table below: Temp. Rise* 1 Unit 2Units 3 Units 3 Units (° F.) GPM GPM GPM GPH 140° F.  2.4 4.8 7.2 429.9100° F.  3.3 6.7 10.0 600.8 90° F. 3.7 7.4 11.1 688.6 75° F. 4.5 8.913.4 802.4 50° F. 5.6 11.1 15.7 1003.0 25° F. 8.5 15.9 25.4 1521.0*The term “Rise” refers to the temperature of water as it leaves thewater heater minus the temperature of the water entering the waterheater.

Thus, in order to insure a recovery rate of about 800 gallons per hour,one would need about 3 of similar water heaters, using about 550,000BTU/hour.

One of the advantages of an instantaneous water heater is its ability toprovide a continuous supply of hot water. However, since the waterpasses through a heat exchanger, the water must flow through the unitslowly to ensure proper heat transfer.

Therefore, the quantity, or rate, at which the hot water is deliveredcan be significantly less than that provided by a storage water heater.When hot water is utilized at several locations of a facility at thesame time the flow of hot water to each fixture can be severelyrestricted. As a result of the restricted output of instantaneous waterheaters, more than one unit may be required, depending on the numbersand types of sinks and equipment present. Due to the flow limitationsinherent in the design of instantaneous water heaters, some local healthagencies may restrict or prohibit their usage in businesses such asrestaurants.

One embodiment of the invention described herein is a hot water mixingsystem that utilizes at least one hot water heater, such as a standardhot water heater or an on demand hot water heater, one or moresuperheated water expansion tanks, and one or more super high flowmixing valve to deliver a high flow of hot water having about a 90° F.rise, and a recovery rate of between about 400 gallons and 800 gallonsper hour using only about 199,000 BTU.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings form part of the present specification and areincluded to further demonstrate certain aspects of the presentinvention. The invention may be better understood by reference to one ormore of these drawings in combination with the detailed description ofspecific embodiments presented herein.

FIG. 1 shows a diagram of a system for producing demand temperature hotwater using a mixing device with at least one water heater.

FIG. 2 shows a diagram of a system for producing demand temperature hotwater using a mixing device with at least two water heaters.

FIG. 3 shows a diagram of a system for producing demand temperature hotwater using a mixing device with one or more storage tanks.

SUMMARY

The invention described herein comprises a hot water mixing system thatmay utilize at least one water heater (such as a tankless water heater,an on demand water heater, or a conventional water heater) onesuperheated water expansion tank, and a super high flow mixing valve todeliver a high flow of hot water having about a 90° F. rise, and arecovery rate of about 400 gallons per hour to about 800 gallons perhour using only about 199,000 BTU.

One aspect of the current invention is a water heating system thatutilizes a water inlet conduit for supplying water from an externalsource. A first ball stop valve having an inlet and an outlet, and theinlet is in fluid communication with the water conduit supplying coldwater to the system. The outlet is connected to a conduit having abifurcation. One path of the bifurcation leads to a second ball stopvalve, a check valve and a first inlet of a high flow mixing device. Thesecond path of the bifurcation is connected to at least one hot waterheater. The cold water entering the hot water heater becomes superheated and exits the heater to flow into an expansion tanks and througha hot water conduit system, which also leads to a second inlet of themixing device. The mixing device will mix superheated water from theheater and cold water to expel hot water that is at a predeterminedtemperature. The water heating system combines a water heater or waterheaters, such as a standard hot water heater or an on demand hot waterheater, expansion tanks and mixing valve for energy efficient and highflow rate alternative to conventional hot water heaters.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Terms: It will be readily apparent to one skilled in the art thatvarious substitutions and modifications may be made in the inventiondisclosed herein without departing from the scope and spirit of theinvention.

The term “a” or “an” as used herein in the specification may mean one ormore. As used herein in the claim(s), when used in conjunction with theword “comprising”, the words “a” or “an” may mean one or more than one.As used herein “another” may mean at least a second or more.

The term “Booster Heater” as used herein refers to an instantaneouswater heater designed and intended to raise the temperature of hot waterto a higher temperature for a specific purpose, such as for thesanitizing rinse on a high temperature automatic dish machine andlaundromat machines.

The term “British Thermal Unit” (“BTU”) as used herein refers to thequantity of heat required to raise the temperature of one pound of waterone degree Fahrenheit.

The term “Gallons Per Hour” (“GPH”) as used herein refers to the amountof water, in gallons, that is used each hour by the plumbing fixturesand equipment, such as dish machines and laundromat machines.

The term “Gallons Per Minute” (“GPM”) as used herein refers to theamount of water, in gallons, flowing through a plumbing fixture orthrough an instantaneous water heater per minute.

The term “Instantaneous Water Heater” as used herein refers to a waterheater that generates hot water on demand.

The term “Kilowatt” (“KW”) as used herein refers to a unit of electricpower equal to 1,000 watts.

The term “Rise” as used herein refers to the temperature of water as itleaves the water heater minus the temperature of the water entering thewater heater.

The term “Storage Water Heater” as used herein refers to a water heaterthat incorporates a thermostat, a storage tank, and a burner or heatingelements, to heat and maintain the water within the tank at a specifictemperature.

The term “Super Heated Water Storage Tank” as used herein refers to astorage tank that receives superheated water for a period of time duringpeak hot water demand.

The term “Thermal Efficiency” as used herein refers to the measure ofthe overall efficiency of the water heater, taking Water HeaterGuidelines into consideration loss of energy due to combustion,radiation, convection and conduction of heat from the unit.

The term “Water Heater” or “Hot Water Heater” as used herein may referto an on-demand water heater, a tankless water heater, a standard waterheater, or a number of other embodiments for heating water to a desiredtemperature.

The term “Valve” as used herein may refer to a check valve, a ballvalve, a regulating flow valve, a tempering valve, a pressure regulatorvalve, or a number of other types of valves for regulating the flow offluid.

A preferred embodiment of the invention comprises at least one waterheater and a mechanism for mixing heated water with cold water from awater supply. Cold water may be introduced to the system via a coldwater supply conduit, which may contain one or more valves forregulation of the flow of water. The cold water flows through the coldwater supply conduit to a bifurcation. One bifurcated path may compriseone or more valves for regulation of the flow of water and leads to acold water supply inlet of a mixing device, preferable a temperingmixing valve. The second bifurcated path allows water to flow into awater heater, preferably a conventional forced air downdraft heater or atankless water heater or an on demand water heater. The water heaterand/or the cold water supply conduit may have one or more safety valves,and may be in connection with one or more expansion tanks. The waterheater is in fluid communication with a super heated water supply inletof the mixing device. Water from the cold water supply inlet of themixing device is mixed with water from the super heated water supplyinlet of the mixing device to discharge water of the desiredtemperature.

A second preferred embodiment of the invention comprises at least twowater heaters connected in parallel and a mechanism for mixing heatedwater with cold water from a water supply. Cold water may be introducedto the system via a cold water supply conduit, which may contain one ormore valves for regulation of the flow of water. The cold water flowsthrough the cold water supply conduit to a bifurcation. One bifurcatedpath may comprise one or more valves for regulation of the flow of waterand leads to a cold water supply inlet of a mixing device, preferable atempering mixing valve. The second bifurcated path allows water to flowinto the two or more water heaters, preferably conventional forced airdowndraft heaters or tankless water heaters or on demand water heaters.The water heaters and/or the cold water supply conduit may have one ormore safety valves, and may be in connection with one or more expansiontanks. The water heaters are in fluid communication with a super heatedwater supply inlet of the mixing device. Water from the cold watersupply inlet of the mixing device is mixed with water from the superheated water supply inlet of the mixing device to discharge water of thedesired temperature.

A third preferred embodiment of the invention comprises at least onewater heater, a storage tank, and a mechanism for mixing heated waterwith cold water from a water supply. Cold water may be introduced to thesystem via a cold water supply conduit, which may contain one or morevalves for regulation of the flow of water. The cold water flows throughthe cold water supply conduit to a bifurcation. One bifurcated path maycomprise one or more valves for regulation of the flow of water andleads to a cold water supply inlet of a mixing device, preferable atempering mixing valve. The second bifurcated path allows water to flowinto one or more water heaters, preferably a conventional forced airdowndraft heater or a tankless water heater or an on demand waterheater. The water heater and/or the cold water supply conduit may haveone or more safety valves, and may be in connection with one or moreexpansion tanks. The water heater is in fluid communication with a superheated water supply inlet of the mixing device. Water from the coldwater supply inlet of the mixing device is mixed with water from thesuper heated water supply inlet of the mixing device to discharge waterof the desired temperature. The discharged water flows through a conduitinto a storage tank, preferably a tank with a capacity of approximately100-600 gallons. The storage tank may be in contact with a thermometerand may comprise a pressure safety device for monitoring or regulatingthe pressure of the storage tank. The storage tank comprises a conduitfor discharging water when required for use. The storage tank furthercomprises a circulation outlet, which allows water to move from thestorage tank back to the water heater. The flow of water from thestorage tank to the water heater is regulated by a circulating pump,preferably with a capacity of between about 1 gallon/minute and about100 gallons/minute.

EXAMPLES

The following examples are provided to further illustrate this inventionand the manner in which it may be carried out. It will be understood,however, that the specific details given in the examples have beenchosen for purposes of illustration only and not be construed aslimiting the invention.

Example 1

The embodiments shown and described above are only exemplary. Eventhough several characteristics and advantages of the present inventionhave been set forth in the foregoing description together with detailsof the invention, the disclosure is illustrative only and changes may bemade within the principles of the invention to the full extent indicatedby the broad general meaning of the terms used in herein and in theattached claim.

FIG. 1 shows a diagram of a preferred system for super heating water inat least one water heater and mixing hot water and cold water from acold water supply. Cold water from an external source flows into thecold water supply conduit (105) through a first check valve (101A) andthen to a bifurcation (111) in the cold water supply conduit (105). Onebifurcated path is in fluid communication with a second check valve(101B), which is in fluid communication with check valve (103) that isin fluid communication with a cold water supply inlet of a mixing device(150). Ball valves (104) are used to regulate flow into and out-of thehot water heater. The second bifurcated path allows water to into thewater heater (110) that is in fluid connection with a cold water supplyconduit (105) through an inlet located on the hot water heater (110).The cold water supply conduit (105) and the hot water heater (110) havea pop-off safety valve (170). The hot water heater (110) also has anoutlet in fluid connection with a super hot water supply conduit system(120). Both the cold water supply conduit (105) and super hot watersupply conduit systems (120) are in fluid connection with expansiontanks (130). If full demand of hot water is suddenly stopped, the superheated water will try to run back out of the water heater causing soldwater line to heat up. The expansion tank on the cold water line allowsfor hot water expansion in the cold water line because the super heatedwater cannot pass the cold water check valve. The super heated watersupply conduit system (120) is in fluid communication with a third checkvalve (101C) that is in fluid communication with a super heated watersupply inlet of the mixing device (150).

The water heater system as shown in FIG. 1, is capable of running alaundromat having about 40 washers with no problems maintaining hotwater supply during peak demand times. The water heater system, is alsocapable of running more washers with a storage tank, as shown in FIG. 3.For example, an embodiment of the system can utilize one water heater199,000 BTU and a 500 gallon storage tank having a circulating pumpbetween the storage tank and water heater. The modified system iscapable of serving a laundromat having about 86 top load washers usingabout 14 gallons of hot water for each approximate 22 minute cycle withlittle or no problems meeting the hot water demand.

Although the system of FIG. 1 is shown with one water heater, at least asecond water heater may be connected to the system depending on the typeof hot water demand that is needed. This second water heater can be usedas a back up heater if the first heater needs service. The additionalhot water heater may be used when the demand for hot water is extremelyhigh for more than about 2-7 hours. Additionally, the heaters could becycled, where one heater could be used one week, and the other would runthe next week. For example, FIG. 2 shows a diagram of a preferred systemfor super heating water in at least two water heaters and mixing hotwater and cold water from a cold water supply. Cold water from anexternal source flows into the cold water supply conduit (105) through afirst check valve (101A) and then to a bifurcation (111) in the coldwater supply conduit (105). One bifurcated path is in fluidcommunication with a second check valve (101B), which is in fluidcommunication with check valve (103) that is in fluid communication witha cold water supply inlet of a mixing device (150). Ball valves (104)are used to regulate flow into and out-of the hot water heaters. Thesecond bifurcated path allows water to into a first and a second hotwater heater (110) that is in parallel fluid connection with a coldwater supply conduit (105) through an inlet located on each of the hotwater heaters (110). The cold water supply conduit (105) and each hotwater heater (110) have a pop-off safety valve (170). Each hot waterheater (110) also has an outlet in parallel fluid connection with asuper hot water supply conduit system (120). Both the cold water supplyconduit (105) and super hot water supply conduit systems (120) are influid connection with expansion tanks (130). The super heated watersupply conduit system (120) is in fluid communication with a third checkvalve (101C) that is in fluid communication with a super heated watersupply inlet of the mixing device (150).

FIG. 3 shows another example of a system for super heating water in atleast one water heater and mixing hot and cold water to obtain water ofa desired temperature. Cold water from an external source flows into thecold water supply conduit (105). Ball valves (104) and check valves(103) are used to regulate flow into and out of a water heater (110).Both the cold water supply conduit (105) and super hot water supplyconduit systems (120) are in fluid connection with expansion tanks(130). The hot water heater (110) has an outlet in parallel fluidconnection with a super hot water supply conduit system (120) that is influid communication with a super heated water supply inlet of the mixingdevice (150). The water discharged (180) from the mixing device (150)may be in contact with a thermometer (195) and a temperature safetydevice (185). The water discharged (180) from the mixing device (150)travels to a storage tank (194). The safety tank is in fluidcommunication with a thermometer (184) and a pressure safety device(170). The water discharged (180) from the storage tank (194) isregulated by a ball valve (104) and is available for use. The exampleshown in FIG. 3 further comprises a mechanism for recirculation of waterfrom the storage tank (194) to the water heater (110) through the actionof a circulating pump (190).

The temperature safety device (185) is capable of monitoring thetemperature of the water discharged (180) from the mixing device (150)and shutting down the apparatus if the temperature deviates from a giventemperature range or number. One of ordinary skill in the art recognizesthat a wide variety of temperature safety devices or similar devicescould be utilized, including commercially available devices fromAquastat or Flowmaster.

The pressure safety device (170) is capable of monitoring thetemperature of the water discharged (180) from the storage tank (194)and shutting down the apparatus if the pressure deviates from a givenacceptable range or number. One of ordinary skill in the art recognizesthat a wide variety of pressure safety devices or similar devices couldbe utilized.

The storage tank (194) may be commercially obtained from a vendor suchas Weben-Jarco, Inc., Williams & Davis, Inc., or Hamilton Engineering.One of ordinary skill in the art recognizes that a wide variety ofstorage tanks or similar devices could be utilized.

The circulating pump (190) may be commercially obtained from a vendorsuch as Gentry, and may vary in capacity depending on the size of thesystem. Examples include pumps such as Dayton, Teel, SURFLO, Jabso,IR-ARO, Flojet, Giant, Taco, Bell and Gossett, Grundfos, Sherwood, andRule. Pumps ranging in capacity from about 1 gallon/minute to about 100gallons/minute may be appropriate. One of ordinary skill in the artrecognizes that a wide variety of pumps or similar devices could beutilized, including commercially available pumps from Bell and Gossett,Inc.

The mixing device (150) described in FIGS. 1-2 are commerciallyavailable from Conbraco Inc. (Matthews, N.C.). This valve, one keyelement of the invention, is a high-velocity valve capable of deliveringover 300 gallons/minute of heated water, even as high as 600gallons/minute. Such a valve may range from approximately 1 inch to 4inches in diameter. This valve is described in detail in U.S. Pat. No.6,328,219 issued to Taylor et al., on Dec. 11, 2001 and titled“Temperature-Responsive Mixing Valve,” (“the '219 patent”) the entirecontent of which is herein incorporated by reference. Generally, the'219 patent is one type of mixing valve that is useful for thisinvention comprises a temperature-actuated mixing valve for controllingoutlet temperature in a fluid flow system including a valve housinghaving first and second fluid supply inlets for introducing first andsecond respective supply fluids and a fluid outlet for dispensing afluid at a predetermined outflow temperature. The mixing valve includesa shuttle assembly positioned in the housing. The shuttle assemblyincludes a valve member mounted for movement within the housingresponsive to the temperature of the supply fluids to vary the mixtureratio of the first and second supply fluids as required to dispensefluid at the predetermined outflow temperature. A shuttle member ispositioned within the valve member and is moveable as a unit therewithwithin a predetermined range of motion responsive to supply fluidtemperature variation. A thermal actuator is provided of the type whichconverts thermal energy into mechanical movement by movement of apiston. A first end of the thermal element engages the movable shuttlemember and an opposing second end engages a stationary portion of thehousing whereby movement of the piston of the thermal actuator producescorresponding movement of the valve member. An overtravel spring iscaptured in a tensioned condition between the valve member and theshuttle member for maintaining the shuttle member and the valve memberin a stationary condition relative to each other within thepredetermined range of motion of the valve member and for permittingmovement of the shuttle member relative to the valve member sufficientto accommodate movement of the piston of the thermal actuator when thevalve member has reached its limit of travel without accommodating thefull extent of movement of the piston of the thermal actuator.

One of ordinary skill in the art understands that hot water mixingvalves similar to the system described above can be utilized.

One of ordinary skill in the art understands that there are severalsimilar types of water heaters that can be utilized with the systemdescribed above. Some examples of water heaters are: the AO SmithCyclone Model BTH-199; Reem Vangaurd Grainger Model No: 6743; BradfordWhite Hydrojet Commercial Model D80T-199E-3N; and other similar waterheaters from suppliers such as Weber Jarco, Reem; A.O. Smith Standard;Bradford White; Hamilton; Dayton; Larther; Sand Blaster; Lavzerss;Natco; E.V.O; Anderson; and U.S. Tank Master.

One of ordinary skill in the art understands that there are severalsimilar types of ball valves that can be utilized with the systemdescribed above. Some examples of ball valves are: from Boston USAD9101,USAD 9201; Locke M568; M929 and M935; and other similar ball valvesavailable from: Boston; U.S. Brass; Asco; Brass Craft; Watts; Conbraco;Nebco; Jamesbury; Dyna Quip; Afllo; George Fischer; Capitol; Sharon;Fermco; Beck; Parker; Cash ACME. Similarly, check valves and reliefvalves such as Granger No GNN89; Conbraco Grainger No. 6K088; WattsGrainger No.: 4A815; Wats Loke No. E96-40L-8-150; Cash ACME Locke No:E579-FWL-2 and Watts Locke No. E100XL-150; and other similar valves thatare available from: Woodforth; Oatey; P.P.P. Inc.; Studor; Fluidmaster;Pasco; Kirkhill; soiqia; Anderson; B and K; Dayton; and Dormont.

One of ordinary skill in the art understands that there are severalsimilar types of safety pop off valves from: Watts; Conbraco; Parker,Nebxo; U.S. Brass; Brass Craft; Anderson; Beck; Capitol; Dayton; Boston;Asco.

Although a specific example for a laundromat hot water system wasdescribed above, one of ordinary skill in the art will understand thatsuch a system could be utilized for meeting the hot water demands ofhotels, restaurants, car washes, hospitals, nursing homes, and otherfacilities. Additionally, such a system could be modified to work aspool and spa heaters.

For conventional hot water heaters, the recovery rate is typically theamount of time it takes to heat water from about 70° F. to about 120° F.Most recovery rates are measured in hours, for example if a home orrestaurant has a demand of 100 gallons of hot water (120° F.) per hour(“GPH”), the water heating system must produce at least 100 gallons of120° F. hot water per hour to have a 100% recovery rate per hour. If thehome or restaurant has a demand of about 800 gallons of hot water perhour, the water heating system must produce at least 800 gallons of hotwater per hour to have a 100% recovery rate per hour. Many largecapacity conventional water heaters use about 1.2-1.4 million BTU's toachieve and maintain hot water to have about an 800 gal/hour recoveryrate. As discussed above, one way to get a similar recovery rate of 800gal/hour is to use a bank of about 6-8 or more conventional hot waterheaters having the same capacity and using the same BTU, which will takenormal temperature water (i.e. about 70° F.) and raise the temperatureto about 120° F.

A more efficient way to achieve the same recovery rate of about 800gallons/hour is to use the water heating and high flow mixing systemthat is shown in FIG. 1. An efficient range of operation temperaturesfor hot water heaters, such as standard hot water heaters or on demandhot water heaters, is about 140° F.-160° F. Cold water having atemperature of about 70° F. can be mixed with super heated water havinga temperature of about 160° F., which results in heated water having atemperature of about 120° F. The super high flow mixing valve controlsthe flow of super heated hot water, and the expansion tanks are used tohold super heated water having a temperature above 1400F. As demandincreases the mixing device brings more super heated hot water into thesystem. It is possible to get about an 800 gal/hour recovery rate usingonly about 398,000 BTU with at least two heaters, which is about aquarter of the energy required to maintain hot water for peak demandtimes in many large capacity conventional water heaters.

While the systems and methods of this invention have described in termsof preferred embodiments, it will be apparent to those of skill in theart that variations may be applied to the systems, methods, and in thesteps or in the sequence of steps of the method described herein withoutdeparting from the concept, spirit and scope of the invention. Morespecifically, it will be apparent that certain materials that are bothfunctionally and mechanically related might be substituted for thematerials described herein while the same or similar results would beachieved. All such similar substitutes and modifications to thoseskilled in the art are deemed to be within the spirit, scope and conceptof the invention as defined by the appended claims.

REFERENCES CITED

The following references, to the extent that they provide exemplaryprocedural or other details supplementary to those set forth herein, arespecifically incorporated herein by reference.

U.S. Patent Documents

-   U.S. Pat. No. 6,943,325 issued to Pittman, et al., on Sep. 13, 2005    and titled “Water Heater.”-   U.S. Pat. No. 6,853,803 issued to Chen, et al., on Feb. 8, 2005 and    titled “High-Performance Water Heater.”-   U.S. Pat. No. 6,577,817 issued to Harris on Jun. 10, 2003 and titled    “Water Heater.”-   U.S. Pat. No. 6,328,219 issued to Taylor et al., on Dec. 11, 2001    and titled “Temperature-Responsive Mixing Valve.”-   U.S. Pat. No. 4,150,665, issued to Wolfson on Apr. 24, 1979, and    titled “Heater For Hot Tubs and Storage Tanks.”-   U.S. Pat. No. 2,633,108 issued to Sterick on Oct. 4, 1950 and titled    “Sterilizing Water Heater.”-   U.S. Pat. No. 1,991,980 issued to Hetzer, on Aug. 11, 1935 and    titled “Water Reclaimer.”-   U.S. Pat. No. 1,560,528 issued to Baum on Apr. 25, 1924, and titled    “Hot Water Heating System.”

1. A water heating system comprising: (a) a water inlet conduit for supplying water from an external source; (b) a first valve having an inlet and an outlet, wherein the inlet of the first valve is in fluid communication with the water inlet conduit, and the outlet of the first valve is in fluid communication with a water conduit having a bifurcation with at least a first and a second bifurcated path; (c) a second valve having an inlet and an outlet, wherein the inlet of the second valve is in fluid communication with the outlet of the first valve through the first bifurcated path of the water conduit; (d) a mixing valve having a first inlet, a second inlet, and an outlet, wherein the first inlet of the mixing valve is in fluid communication with the outlet of the second valve; (e) a hot water heater having an inlet port and an outlet port, wherein the inlet port of the hot water heater is in fluid communication with the second bifurcated path of the water conduit; (f) a hot water expansion tank in fluid communication with the hot water heater; (g) a third valve having an inlet and an outlet, wherein the hot water heater and the hot water expansion tank are in fluid communication with the inlet of the third valve, and the outlet of the third valve is in fluid communication with the second inlet of the mixing valve; and (h) a hot water conduit in fluid communication with the outlet of the mixing valve.
 2. A process for producing hot water using the water heating system of claim 1 comprising: (a) allowing the water from an external source to flow into the water inlet conduit, subsequently flowing through the inlet of the first valve, followed by flowing through the outlet of the first valve, and then flowing through the water conduit reaching the first and the second bifurcated paths of the water conduit; (b) allowing a first portion of the water reaching the water conduit to flow through the first bifurcated path of the water conduit, then through the inlet of the second valve, subsequently through the outlet of the second valve, and then through the first inlet of the mixing valve; (c) allowing a second portion of the water reaching the water conduit to flow through the second bifurcated path of the water conduit, then through the inlet port of the hot water heater, subsequently through the outlet port of the hot water heater, then through the inlet of the third valve, subsequently through the outlet of the third valve, and then through the second inlet of the mixing valve; (d) allowing water from the first inlet of the mixing valve to combine with water from the second inlet of the mixing valve to give a heated water; and (e) allowing the heated water to flow through the outlet of the mixing valve to the hot water conduit.
 3. The water heating system of claim 1, wherein the water conduit is in fluid contact with a pop-off safety valve or an expansion tank.
 4. The water heating system of claim 1, wherein the hot water heater is in fluid communication with a pop-off safety valve or an expansion tank.
 5. The water heating system of claim 1, wherein the hot water heater inlet port or outlet port comprises a ball valve.
 6. The water heating system of claim 1, wherein the hot water conduit is in fluid communication with a thermometer or temperature safety device.
 7. A water heating system comprising: (a) a water inlet conduit for supplying water from an external source; (b) a first valve having an inlet and an outlet, wherein the inlet of the first valve is in fluid communication with the water inlet conduit, and the outlet of the first valve is in fluid communication with a water conduit having a bifurcation with at least a first and a second bifurcated path; (c) a second valve having an inlet and an outlet, wherein the inlet of the second valve is in fluid communication with the outlet of the first valve through the first bifurcated path of the water conduit; (d) a mixing valve having a first inlet, a second inlet, and an outlet, wherein the first inlet of the mixing valve is in fluid communication with the outlet of the second valve; (e) one or more hot water heaters, each having an inlet port and an outlet port, wherein the inlet port of each hot water heater is in fluid communication with the second bifurcated path of the water conduit; (f) one or more hot water expansion tanks in fluid communication with one or both of the hot water heaters; (g) a third valve having an inlet and an outlet, wherein each of the hot water heaters and each of the hot water expansion tanks are in fluid communication with the inlet of the third valve, and the outlet of the third valve is in fluid communication with the second inlet to the mixing valve; and (h) a hot water conduit in fluid communication with the outlet of the mixing valve.
 8. A process for producing hot water using the water heating system of claim 7 comprising: (a) allowing the water from an external source to flow into the water inlet conduit, subsequently flowing through the inlet of the first valve, followed by flowing through the outlet of the first valve, and then flowing through the water conduit reaching the first and the second bifurcated paths of the water conduit; (b) allowing a first portion of the water reaching the water conduit to flow through the first bifurcated path of the water conduit, then through the inlet of the second valve, subsequently through the outlet of the second valve, and then through the first inlet of the mixing valve; (c) allowing a second portion of the water reaching the water conduit to flow through the second bifurcated path of the water conduit, then through the inlet port of one or more of the hot water heaters, subsequently through the outlet port of one or more of the hot water heaters, then through the inlet of the third valve, subsequently through the outlet of the third valve, and then through the second inlet of the mixing valve; (d) allowing water from the first inlet of the mixing valve to combine with water from the second inlet of the mixing valve to give a heated water; and (e) allowing the heated water to flow through the outlet of the mixing valve to the hot water conduit.
 9. The water heating system of claim 7, wherein the water conduit is in fluid communication with a pop-off safety valve or an expansion tank.
 10. The water heating system of claim 7, wherein one or more of the hot water heaters is in fluid contact with a pop-off safety valve or an expansion tank.
 11. The water heating system of claim 7, wherein one or more of the hot water heater inlet ports or hot water heater outlet ports comprises a ball valve.
 12. The water heating system of claim 7, wherein the hot water conduit is in fluid communication with a thermometer or temperature safety device.
 13. A water heating system comprising: (a) a water inlet conduit for supplying water from an external source; (b) a first valve having an inlet and an outlet, wherein the inlet of the first valve is in fluid communication with the water inlet conduit, and the outlet of the first valve is in fluid communication with a water conduit having a bifurcation with at least a first and a second bifurcated path; (c) a second valve having an inlet and an outlet, wherein the inlet of the second valve is in fluid communication with the outlet of the first valve through the first bifurcated path of the water conduit; (d) a mixing valve having a first inlet, a second inlet, and an outlet, wherein the first inlet of the mixing valve is in fluid communication with the outlet of the second valve; (e) one or more hot water heaters, each having an inlet port in fluid communication with the second bifurcated path of the water conduit; (f) one or more hot water expansion tanks in fluid communication with one or both of the hot water heaters; (g) a third valve having an inlet and an outlet, wherein the third valve inlet is in fluid communication with each of the hot water heaters and each of the hot water expansion tanks, and the third valve outlet is in fluid communication with the second inlet to the mixing valve; (h) a discharged water conduit in fluid communication with the outlet of the mixing valve; (i) a storage tank having an inlet, a first outlet, and a second outlet, wherein the storage tank inlet is in fluid communication with the discharged water conduit; (j) a fourth valve having an inlet and an outlet, wherein the inlet of the fourth valve is in fluid communication with the first outlet of the storage tank and wherein the outlet of the fourth valve is in fluid communication with a recirculation conduit; (k) a recirculation pump having an inlet and an outlet, wherein the inlet of the recirculation pump is in fluid communication with the recirculation conduit and the outlet of the recirculation pump is in fluid communication with one or both of the hot water heaters; and (l) a fifth valve having an inlet and an outlet wherein the inlet of the fifth valve is in fluid communication with the second outlet of the storage tank and the outlet of the fifth valve is in fluid communication with a hot water conduit.
 14. A process for producing hot water using the water heating system of claim 13 comprising: (a) allowing the water from an external source to flow into the water inlet conduit, subsequently flowing through the inlet of the first valve, followed by flowing through the outlet of the first valve, and then flowing through the water conduit reaching the first and the second bifurcated paths of the water conduit; (b) allowing a first portion of the water reaching the water conduit to flow through the first bifurcated path of the water conduit, then through the inlet of the second valve, subsequently through the outlet of the second valve, and then through the first inlet of the mixing valve; (c) allowing a second portion of the water reaching the water conduit to flow through the second bifurcated path of the water conduit, then through the inlet port of one or more of the hot water heaters, subsequently through the outlet port of one or more of the hot water heaters, then through the inlet of the third valve, subsequently through the outlet of the third valve, and then through the second inlet of the mixing valve; (d) allowing water from the first inlet of the mixing valve to combine with the water from the second inlet of the mixing valve to give a heated water; (e) allowing the heated water to flow through the outlet of the mixing valve to the discharged water conduit, then through the inlet of the storage tank to reach the storage tank; (f) allowing a first portion of the water reaching the storage tank to flow through the inlet of the fourth valve, subsequently through the outlet of the fourth valve, then through the recirculation conduit, then through the inlet of the recirculation pump, subsequently through the outlet of the recirculation pump, then through the inlet port of one or more of the hot water heaters; and (g) allowing a second portion of the water reaching the storage tank to flow through the second outlet of the storage tank, then through the outlet of the fifth valve, subsequently through the hot water conduit.
 15. The water heating system of claim 13, wherein the water conduit is in fluid communication with a pop-off safety valve or an expansion tank.
 16. The water heating system of claim 13, wherein one or more of the hot water heaters is in fluid communication with a pop-off safety valve or an expansion tank.
 17. The water heating system of claim 13, wherein the discharged water conduit is in fluid communication with a thermometer or a temperature safety device.
 18. The water heating system of claim 13, wherein the hot water conduit is in fluid communication with a thermometer or a temperature safety device.
 19. The water heating system of claim 13, wherein the storage tank is in fluid communication with a thermometer or a temperature safety device.
 20. The water heating system of claim 13, wherein the storage tank is in fluid communication with a pressure safety device. 